A deadly rampage in an American mall has left at least four persons dead, local media reports said Sunday.

The attack occurred during a video game competition at a shopping centre in Jacksonville, Florida, south of the United States.

Multiple media reports, including by the Associated Press, cited law enforcement officials as confirming four people were killed out of about a dozen people who were shot.

The attacker also took own life. It was not immediately clear whether all threats have been neutralised.

The attacker struck at the Jacksonville Landing complex while a qualifying game for Madden 19 Tournament was underway at the GLHF Game Bar, CompLexity Gaming, one of the gaming teams, posted on Twitter Sunday night.

Memorial Hospital in Jacksonville is said to be treating some of the wounded.

A spokesperson for Donald Trump said the president has been monitoring the situation, and all necessary support would be provided to victims and responders.